Soluble urokinase plasminogen activator receptor predicts mortality in exacerbated COPD

Factors associated with risk of death in hospitalized patients for exacerbation of chronic obstructive pulmonary disease: an updated scoping review

INTRODUCTION

The Exacerbation of Chronic Obstructive Pulmonary Disease (ECOPD), especially if leading to hospitalization, increases the risk of death. Our scoping review aims to identify updated mortality risk factors for both short- and long-term periods.

AREAS COVERED

A comprehensive search, covering the period from January 2013 to February 2024, was performed to identify eligible studies that consider factors associated with death in hospitalized ECOPD. We considered short-term mortality, up to one year (including in-hospital mortality, IHM) and long-term mortality over one year, without time limits. We excluded studies concerning the intensive care area.

EXPERT OPINION

We considered 38 studies, 32 and 8 reporting data about short- and long-term mortality, respectively. Two studies consider both periods. Several factors, some already known, others newly identified, have been evaluated and discussed. Some of these were related to the characteristics and severity of COPD (age, body mass index, lung impairment), and some considered the response to ECOPD. In this last context, we focused on the increasing role of biomarkers in predicting the mortality of patients, particularly IHM. Our factors associated with a worse prognosis may be helpful in clinical practice to identify patients at risk and, subsequently, determine a personalized approach.

Early detection and prediction of acute exacerbation of chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation. Acute exacerbation of COPD (AECOPD) is an acute worsening of respiratory symptoms, which needs additional treatment and can result in worsening health status, increasing risks of hospitalization and mortality. Therefore, it is necessary to early recognize and diagnose exacerbations of COPD. This review introduces the updated definition of COPD exacerbations, the current clinical assessment tools, and the current potential biomarkers. The application of mobile health care in COPD management for early identification and diagnosis is also included in this review.

Low diastolic blood pressure and adverse outcomes in inpatients with acute exacerbation of chronic obstructive pulmonary disease: A multicenter cohort study

BACKGROUND

Although intensively studied in patients with cardiovascular diseases (CVDs), the prognostic value of diastolic blood pressure (DBP) has little been elucidated in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study aimed to reveal the prognostic value of DBP in AECOPD patients.

METHODS

Inpatients with AECOPD were prospectively enrolled from 10 medical centers in China between September 2017 and July 2021. DBP was measured on admission. The primary outcome was all-cause in-hospital mortality; invasive mechanical ventilation and intensive care unit (ICU) admission were secondary outcomes. Least absolute shrinkage and selection operator (LASSO) and multivariable Cox regressions were used to identify independent prognostic factors and calculate the hazard ratio (HR) and 95% confidence interval (CI) for adverse outcomes.

RESULTS

Among 13,633 included patients with AECOPD, 197 (1.45%) died during their hospital stay. Multivariable Cox regression analysis showed that low DBP on admission (<70 mmHg) was associated with increased risk of in-hospital mortality (HR = 2.16, 95% CI: 1.53-3.05, Z = 4.37, P <0.01), invasive mechanical ventilation (HR = 1.65, 95% CI: 1.32-2.05, Z = 19.67, P <0.01), and ICU admission (HR = 1.45, 95% CI: 1.24-1.69, Z = 22.08, P <0.01) in the overall cohort. Similar findings were observed in subgroups with or without CVDs, except for invasive mechanical ventilation in the subgroup with CVDs. When DBP was further categorized in 5-mmHg increments from <50 mmHg to ≥100 mmHg, and 75 to <80 mmHg was taken as reference, HRs for in-hospital mortality increased almost linearly with decreased DBP in the overall cohort and subgroups of patients with CVDs; higher DBP was not associated with the risk of in-hospital mortality.

CONCLUSION

Low on-admission DBP, particularly <70 mmHg, was associated with an increased risk of adverse outcomes among inpatients with AECOPD, with or without CVDs, which may serve as a convenient predictor of poor prognosis in these patients.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trail Registry, No. ChiCTR2100044625.

Is analysis of inflammatory biomarkers and lymphocyte subpopulations useful in prediction of tuberculosis treatment outcomes?

Analysis of inflammatory biomarkers and lymphocytes during the treatment of tuberculosis (TB) could yield findings that influence the routine clinical practice and use of new anti-TB drugs. This study aimed to evaluate whether the selected biomarkers-soluble intercellular adhesion molecule type 1, soluble urokinase-type plasminogen activator receptor (suPAR), and C-reactive protein (CRP)-and T-cell subpopulations are useful for predicting culture conversion, treatment outcomes, and the extent of radiological lesions (calculated using X-ray score) in patients with drug-sensitive pulmonary TB. This study included 62 patients with drug-sensitive pulmonary TB. CRP and suPAR levels significantly decreased after 1 month of treatment. Before treatment initiation, CRP and suPAR levels were significantly higher in patients without culture conversion; however, none of the selected host biomarkers appeared to significantly influence the conversion status or treatment outcomes. Some lymphocyte subpopulations were correlated with X-ray scores before TB treatment initiation, but lung destruction, as determined using X-ray scores, showed the highest correlation with the baseline CRP value. We conclude that selected host biomarkers have a very limited role in predicting TB treatment outcomes and culture conversion and do not appear to be superior to CRP in monitoring TB treatment.

Prediction of gold stage in patients hospitalized with COPD exacerbations using blood neutrophils and demographic parameters as risk factors

Background

Patients hospitalized with chronic obstructive pulmonary disease (COPD) exacerbations are unable to complete the pulmonary function test reliably due to their poor health conditions. Creating an easy-to-use instrument to identify the Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage will offer valuable information that assists clinicians to choose appropriate clinical care to decrease the mortality in these patients. The objective of this study was to develop a prediction model to identify the GOLD stage in the hospitalized exacerbation of chronic obstructive pulmonary disease (ECOPD) patients.

Methods

This prospective study involved 155 patients hospitalized for ECOPD. All participants completed lung function tests and the collection of blood neutrophils and demographic parameters. Receiver operating characteristic (ROC) curve was plotted based on the data of 155 patients, and was used to analyze the disease severity predictive capability of blood neutrophils and demographic parameters. A support vector regression (SVR) based GOLD stage prediction model was built using the training data set (75%), whose accuracy was then verified by the testing data set (25%).

Results

The percentage of blood neutrophils (denoted as NEU%) combined with the demographic parameters was associated with a higher risk to severe episode of ECOPD. The area under the ROC curve was 0.84. The SVR model managed to predict the GOLD stage with an accuracy of 90.24%. The root-mean-square error (RMSE) of the forced expiratory volume in one second as the percentage of the predicted value (denoted as FEV₁%pred) was 8.84%.

Conclusions

The NEU% and demographic parameters are associated with the pulmonary function of the hospitalized ECOPD patients. The established prediction model could assist clinicians in diagnosing GOLD stage and planning appropriate clinical care.

suPAR Cut-Offs for Risk Stratification in Patients With Symptoms of COVID-19

Objectives

Elevated soluble urokinase Plasminogen Activator Receptor (suPAR) is a biomarker associated with adverse outcomes. We aimed to investigate the associations between plasma suPAR levels (testing the cut-offs ⩽4, 4-6, and ⩾6 ng/mL) with risk of 14-day mortality, and with the risk of mechanical ventilation in patients that tested positive for SARS-CoV-2.

Methods

Observational cohort study of patients presenting with symptoms of COVID-19 at Department of Emergency Medicine, Amager and Hvidovre Hospital, Denmark from March 19th, 2020 to April 3rd, 2020. Plasma suPAR was measured using suPARnostic technologies. Patients were followed for development of mechanical ventilation and mortality for 14 days. Validation of our findings were carried out in a similar sized COVID-19 patient cohort from Mikkeli Central Hospital, Finland.

Results

Among 386 patients with symptoms of COVID-19, the median (interquartile range) age was 64 years (46-77), 57% were women, median suPAR was 4.0 ng/mL (2.7-5.9). In total, 35 patients (9.1%) died during the 14 days follow-up. Patients with suPAR ⩽4 ng/mL (N = 196; 50.8%) had a low risk of mortality (N = 2; 1.0%; negative predictive value of 99.0%, specificity 55.3%, sensitivity 95.2%, positive predictive value 17.4%). Among patients with suPAR ⩾6 ng/mL (N = 92; 23.8%), 16 died (17.4%). About 99 patients (25.6%) tested positive for SARS CoV-2 and of those 12 (12.1%) developed need for mechanical ventilation. None of the SARS-CoV-2 positive patients with suPAR ⩽4 ng/mL (N = 28; 38.8%) needed mechanical ventilation or died. The Mikkeli Central Hospital validation cohort confirmed our findings concerning suPAR cut-offs for risk of development of mechanical ventilation and mortality.

Conclusions

Patients with symptoms of COVID-19 and suPAR ⩽4 or ⩾6 ng/mL had low or high risk, respectively, concerning the need for mechanical ventilation or mortality. We suggest cut-offs for identification of risk groups in patients presenting to the ED with symptoms of or confirmed COVID-19.

Value of refined care in patients with acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Under physiological conditions, sputum produced during acute exacerbation of chronic obstructive pulmonary disease (AECOPD) can move passively with the cilia in the airway; the sputum is gradually excreted from the depth of the airways through the stimulation of the coughing reflex on the sensory nerve on the surface of the airway. However, when the sputum is thick, the cough is weak, or the tracheal cilia are abnormal, sputum accumulation may occur and affect the exchange of oxygen and carbon dioxide in the lung. Furthermore, the presence of pathogenic microorganisms in sputum may cause or aggravate the symptoms of pulmonary infection in patients, which is the main factor leading to AECOPD. Therefore, promoting effective drainage of sputum and maintaining airway opening are key points requiring clinical attention.

AIM

To explore the effect of refined nursing strategies in patients with AECOPD and dysphagia.

METHODS

We selected 126 patients with AECOPD and difficulty of expectoration at our hospital, and divided them into a refined care group and a routine care group, with 63 cases each, using a random number table. The two groups of patients were treated with expectorant, anti-infection, oxygen inhalation, and other basic treatment measures; patients in the refined care group were given refined nursing intervention during hospitalization, and the routine care group received conventional nursing intervention. The differences in sputum expectoration, negative pressure suction rate, blood gas parameters, dyspnea score measured through the tool developed by the Medical Research Council (MRC), and quality of life were compared between the two groups.

RESULTS

After 7 d of intervention, the sputum expectoration effect of the refined care group was 62.30%, the effective rate was 31.15%, and the inefficiency rate was 6.56%. The sputum expectoration effect of the routine care group was 44.07%, the effective rate was 42.37%, and the inefficiency rate was 13.56%. The refined care group had better sputum expectoration than the routine care group (P < 0.05). The negative pressure suction rate in the refined care group was significantly lower than that of the routine care group during the treatment (22.95% vs 44.07%, P < 0.05). Before the intervention, the arterial oxygen saturation (PaO₂) and arterial carbon dioxide saturation (PaCO₂) values were not significantly different between the two groups (P > 0.05); the PaO₂ and PaCO₂ values in the refined care group were comparable to those in the routine care group after 7 d of intervention (P > 0.05). Before the intervention, there was no significant difference in the MRC score between the two groups (P > 0.05); the MRC score of the refined care group was lower than that of the routine care group after 7 d of intervention, but the difference was not statistically significant (P > 0.05). Before intervention, there was no significant difference in the symptoms, activities, disease impact, or St. George’s Respiratory questionnaire (SGRQ) total scores between the two groups (P> 0.05). After 7 days of intervention, the symptoms, activities, and total score of SGRQ of the refined care group were higher than those of the routine care group, but the difference was not statistically significant (P > 0.05).

CONCLUSION

AECOPD with thick sputum, weak coughing reflex, and abnormal tracheal cilia function will lead to sputum accumulation and affect the exchange of oxygen and carbon dioxide in the lung. Patients with AECOPD who have difficulty expectorating sputum may undergo refined nursing strategies that will promote expectoration, alleviate clinical symptoms, and improve the quality of life.

Using soluble urokinase plasminogen activator receptor to stratify patients for medication review in the emergency department

AIMS

To investigate whether the association between levels of medication use (including polypharmacy and potentially inappropriate medications [PIMs]) and health outcomes such as readmission and mortality is dependent on baseline soluble urokinase plasminogen activator receptor (suPAR).

METHODS

This registry-based cohort study included medical patients admitted to the emergency department at Copenhagen University Hospital Hvidovre, Denmark. Patients were grouped according to their admission suPAR levels: low (0-3 ng/mL), intermediate (3-6 ng/mL), or high (>6 ng/mL). Hyper-polypharmacy was defined as ≥10 prescribed medications. PIMs were identified based on the EU(7)-PIM list, and data on admissions and mortality were obtained from national registries. Risk of 90-day readmission and mortality was assessed by Cox regression analysis adjusted for sex, age and Charlson comorbidity index. Results were reported as hazard ratios within 90 days of index discharge.

RESULTS

In total, 26 291 patients (median age 57.3 y; 52.7% female) were included. Risk of 90-day readmission and mortality increased significantly for patients with higher suPAR or higher number of medications. Among patients with low suPAR, patients with ≥10 prescribed medications had a hazard ratio of 2.41 (95% confidence interval = 2.09-2.78) for 90-day readmission and 8.46 (95% confidence interval = 2.53-28.28) for 90-day mortality compared to patients with 0 medications. Patients with high suPAR generally had high risk of readmission and mortality, and the impact of medication use was less pronounced in this group. Similar, but weaker, association patterns were observed between suPAR and PIMs.

CONCLUSION

The association between levels of medication use and health outcomes is dependent on baseline suPAR.

Time-resolved proteomic profiling of cigarette smoke-induced experimental chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is the third leading cause of illness and death worldwide. Current treatments aim to control symptoms with none able to reverse disease or stop its progression. We explored the major molecular changes in COPD pathogenesis.

METHODS

We employed quantitative label-based proteomics to map the changes in the lung tissue proteome of cigarette smoke-induced experimental COPD that is induced over 8 weeks and progresses over 12 weeks.

RESULTS

Quantification of 7324 proteins enabled the tracking of changes to the proteome. Alterations in protein expression profiles occurred in the induction phase, with 18 and 16 protein changes at 4- and 6-week time points, compared to age-matched controls, respectively. Strikingly, 269 proteins had altered expression after 8 weeks when the hallmark pathological features of human COPD emerge, but this dropped to 27 changes at 12 weeks with disease progression. Differentially expressed proteins were validated using other mouse and human COPD bronchial biopsy samples. Major changes in RNA biosynthesis (heterogeneous nuclear ribonucleoproteins C1/C2 [HNRNPC] and RNA-binding protein Musashi homologue 2 [MSI2]) and modulators of inflammatory responses (S100A1) were notable. Mitochondrial dysfunction and changes in oxidative stress proteins also occurred.

CONCLUSION

We provide a detailed proteomic profile, identifying proteins associated with the pathogenesis and disease progression of COPD establishing a platform to develop effective new treatment strategies.

Association of soluble urokinase plasminogen activator receptor levels with fibrotic and vascular manifestations in systemic sclerosis

OBJECTIVE

We assessed the association of suPAR (soluble urokinase plasminogen activator receptor) plasma levels with fibrotic and vascular manifestations in patients with systemic sclerosis (SSc).

METHODS

suPAR plasma levels were measured in 121 consecutive patients with SSc and correlated to pulmonary and vascular features of SSc, including interstitial lung disease as characterized by percentage of predicted CO diffusing capacity (DLco) and forced vital capacity (FVC), pulmonary fibrosis by computed tomography, and pulmonary arterial hypertension, telangiectasias, and digital ulcers.

RESULTS

Overall, 121 SSc patients (84% females; mean age, 57 ± 12 [range: 22-79] years) were enrolled; 35% had diffuse cutaneous SSc. suPAR plasma levels ranged from 1.3-10.2 [median: 2.9 (p25-p75: 2.3-3.9)] ng/mL. Log(suPAR) levels correlated with DLco (r = -0.41, p <0.0001) and FVC (r = -0.26, p = 0.004), also when adjusted for age, sex, and pulmonary hypertension. A suPAR cut-off level of >2.5 ng/mL showed a sensitivity of 91% for identifying patients with either DLco <50% or FVC < 60% of the predicted values. Similarly, 19 (90%) had a suPAR >2.5 ng/mL among those diagnosed with pulmonary fibrosis vs. 59 (60%) among those who did not (p = 0.008). suPAR values were not associated with vascular manifestations.

CONCLUSION

suPAR levels strongly correlated with pulmonary involvement in SSc. Future studies should test if suPAR estimation can be used for surveillance of severe pulmonary involvement in SSc.

Serum biomarkers in patients with stable and exacerbated COPD-bronchiectasis overlap syndrome

INTRODUCTION

Bronchiectasis (B), commonly seen in patients with chronic obstructive pulmonary disease (COPD), is associated with exacerbations and predicts mortality.

OBJECTIVES

To differentiate patient groups with COPD-(B+) or COPD-(B-) and their exacerbations by using inflammatory markers.

METHODS

Consecutive COPD patients were divided into two groups according to findings on high resolution thorax CT (HRCT) images using Smith and modified Reiff scores. Patients were prospectively followed for possible future exacerbations. Serum fibrinogen, C-reactive protein (CRP), soluble urokinase-type plasminogen activator receptor (suPAR) and Plasminogen activator inhibitor-1 (PAI-1) levels were studied during exacerbation and stable periods.

RESULTS

Eighty-seven patients were included and (85 M, 2 F), mean aged was 68.1 ± 9 (46-87). HRCT confirmed bronchiectasis in 38 (43.7%) patients, most commonly in tubular form (89.4%) and in lower lobes. COPD-B(+) group had lower body mass index (P = 0.036), more advanced stage of disease (P = 0.004) and more frequent exacerbation (P = 0.01). The HRCT scores were correlated with exacerbation rate (r = 0.356, P < 0.05). Fibrinogen and CRP values were higher in exacerbation (P = 0.01, P = 0.013, respectively) especially in COPD-B(+) patients. suPAR and PAI-1 levels were also higher in COPD-B(+) patients although it was not statistically significant.

CONCLUSION

Bronchiectasis is common and causes frequent exacerbations in COPD. Identifying of COPD-B(+) phenotype by HRCT scoring systems has considerable importance for both therapeutic options and clinical outcome of the disease. In addition to fibrinogen and CRP, high serum levels of suPAR and PAI-1 suggest us their significant roles in increased systemic inflammation associated with coexisting of COPD and bronchiectasis.

The clinical value of suPAR in diagnosis and prediction for patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Soluble urokinase-type plasminogen activator receptor (suPAR) is positively correlated with immune system activity. Inflammation can promote the development of chronic obstructive pulmonary disease (COPD). Therefore, this study conducted a systematic review and meta-analysis to assess the association between suPAR levels and the pathogenesis of COPD, and further assess the exact clinical value of suPAR in COPD.

METHODS

PubMed, Excerpt Medica Database (Embase), Web of Science (WOS), and Cochrane Library databases were searched for studies that reported the value of suPAR diagnosis for adult COPD patients.

RESULTS

A total of 11 studies were included, involving 4520 participants. Both COPD patients with predicted forced expiratory volume in 1 s (FEV1)⩾80% [weighted mean difference (WMD) = 320.25; 95% confidence interval (CI): 99.79-540.71] and FEV1 < 80% (WMD = 2950.74; 95% CI: 2647.06-3254.43) showed higher suPAR level. The sensitivity and specificity of suPAR for diagnosis of COPD were 87% and 79%, respectively, and AUC was 84%. This can not only effectively identify acute exacerbation of COPD (AECOPD) in a healthy population (WMD = 3114.77; 95% CI: 2814.66-3414.88), but also has the potential to distinguish AECOPD from stable COPD (WMD = 351.40; 95% CI: 215.88-486.93). There was a significant decrease of suPAR level after treatment [WMD = -1226.97; 95% CI: -1380.91- (-1073.03)].

CONCLUSION

suPAR as a novel biomarker has potential for early diagnosis of COPD and prediction of AECOPD. There is a potential correlation between the level of suPAR and the state of COPD, which may also indicate the early state and severity of COPD. When the suPAR level of COPD patients is further increased, the risk of acute exacerbation increases and should be highly valued. This also shows potential as a measure of treatment response, and as a guide to the clinical management in COPD. The reviews of this paper are available via the supplemental material section.

Serum β2-Microglobulin is Associated with Mortality in Hospitalized Patients with Exacerbated Chronic Obstructive Pulmonary Disease

Purpose

We hypothesized that increased level of serum β2-microglobulin (β2M) is an independent factor associated with higher mortality in hospitalized patients with exacerbated chronic obstructive pulmonary disease (COPD).

Patients and Methods

We retrospectively analyzed 488 hospitalized patients with exacerbated COPD as the first diagnosis at Beijing Chao-Yang hospital, P. R. China between December 31st, 2012 and December 28th, 2017. Concentrations of serum β2M and other clinical indexes were measured or collected on admission, and all patients were followed up to 90 days. The relationship between β2M and 30- and 90-day all-cause mortality was explored by Cox regression analysis adjusted for age, C-reactive protein values, N-terminal pro-brain natriuretic peptide/100, respiratory failure [RF, defined as partial arterial oxygen pressure (PaO₂) <60 mmHg on room air or PaO₂ over the fraction of inspired oxygen (PaO₂/FiO₂) < 300], eosinopenia, consolidation, and acidaemia.

Results

Median concentrations of β2M were significantly higher in non-survivals compared to survivals within 30 days (4.11 mg/L (IQR 3.10–6.60) vs 2.79mg/L (IQR 2.13–3.76), P < 0.001) and 90 days (3.79 mg/L (IQR 2.61–6.69) vs 2.79 mg/L (IQR 2.13–3.73), P < 0.001). Serum levels of β2M were correlated with 30-day and 90-day mortality in overall exacerbated COPD patients, with hazard ratios (HRs) of 1.09 (95% CI 1.04–1.14, P = 0.001) and 1.09 (95% CI 1.05–1.14, P < 0.001). In exacerbated COPD patients without RF and with RF, the HRs were 1.06 (95% CI 0.995–1.137, P = 0.069) and 1.14 (95% CI 1.02–1.27, P = 0.021) for 30-day mortality, 1.09 (95% CI 1.02–1.15, P = 0.010) and 1.14 (95% CI 1.03–1.26, P = 0.014) for 90-day mortality, respectively.

Conclusion

Our data showed that concentrations of serum β2M were associated with an increased risk of mortality, suggesting that β2M might be a valuable predictor of poor prognosis for hospitalized patients with exacerbated COPD.

High suPAR and Low Blood Eosinophil Count are Risk Factors for Hospital Readmission and Mortality in Patients with COPD

Introduction

The biomarker soluble urokinase plasminogen activator receptor (suPAR) has been associated with increased mortality in chronic obstructive pulmonary disease (COPD), while elevated blood eosinophils have been associated with better survival. We hypothesized that suPAR and blood eosinophil count are independent risk factors for readmission and mortality after an acute admission in patients with COPD.

Methods

This retrospective cohort study comprised 4022 patients with prevalent COPD acutely admitted to Hvidovre Hospital, Denmark. Irrespective of cause of admission, suPAR and blood eosinophils were measured, and patients were followed up to 365 days. Associations with 365-day respiratory readmission, all-cause readmission and all-cause mortality were investigated by Cox regression analyses adjusted for age, sex, Charlson score and C-reactive protein.

Results

suPAR was significantly elevated in patients who later experienced readmission or died. At 365 days, hazard ratios (HRs) for all-cause readmission and mortality reached 1.61 (95% CI 1.40–1.85; p<0.0001) and 3.40 (95% CI 2.64–4.39; p<0.0001), respectively, for COPD patients in the fourth suPAR quartile compared to patients in the first suPAR quartile. High blood eosinophils (>300 cells/μL) were associated with lower risk of mortality (HR 0.49, 95% CI 0.39–0.62; p<0.0001) compared with patients with <150 cells/μL. When stratifying patients by suPAR quartiles and blood eosinophil counts, the highest relative mortality rate was found in patients belonging to both the fourth suPAR quartile and the low blood eosinophil (<150 cells/μL) group.

Conclusion

In this cohort of COPD patients acutely admitted to a hospital, elevated suPAR concentrations were associated with both higher risk of all-cause readmission and mortality, whereas higher blood eosinophil count was associated with lower risk of mortality.

The biomarkers suPAR and blood eosinophils are associated with hospital readmissions and mortality in asthma - a retrospective cohort study

INTRODUCTION

Prognostic biomarkers in asthma are needed. The biomarker soluble urokinase plasminogen activator receptor (suPAR) has been associated with asthma control and with prognosis in acutely admitted medical patients. We investigated if suPAR and blood eosinophil counts at the time of admission for asthma are associated with readmission and mortality.

METHODS

Our cohort comprised 1341 patients (median age 45.3, IQR 30.1-63.1) acutely admitted with a diagnosis of asthma to Hvidovre Hospital, Denmark (November 2013 to March 2017). Patients had suPAR and blood eosinophils measured at admission. Outcomes were 365-day readmission and all-cause mortality. Logistic regression analysis adjusted for age, sex, C-reactive protein, and Charlson comorbidity score was used to assess the association of the two biomarkers with readmission and all-cause mortality.

RESULTS

Compared to event-free patients, patients who were either readmitted (n = 452, 42.3%) or died (n = 57, 5.3%) had significantly higher suPAR concentrations (p < 0.0001) and lower eosinophil counts (p = 0.0031) at admission. The highest odds of readmission or mortality were observed for patients in either the 4th suPAR quartile (p < 0.0001) or with eosinophil counts < 150 cells/μL at admission. Increasing levels of suPAR were associated with 365-day readmission (OR 1.3 [1.0-1.6]; p = 0.05) and mortality (OR 2.9 [1.7-5.1]; p = 0.0002). Eosinophil count > 300 cells/μL was significantly associated with lower odds of readmission (OR 0.64 [0.5-0.9]; p = 0.005) and lower mortality (OR 0.7 [0.6-0.9]; p = 0.0007).

CONCLUSIONS

In patients acutely admitted with asthma, elevated suPAR concentrations together with blood eosinophil count < 150 cells/μL at the time of hospital admission were associated with both 365-day all-cause readmission and mortality.

Increased Serum Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR) Levels in FSGS: A Meta-Analysis

Introduction

The soluble urokinase-type plasminogen activator receptor (suPAR) has been found to be elevated in primary focal segmental glomerulosclerosis (pFSGS). However, its usefulness as a biomarker for FSGS remains controversial. We conducted a meta-analysis aiming at investigating the significance of suPAR in diagnosing pFSGS.

Methods

Electronic databases (PubMed and EMBASE) were searched to identify studies comparing suPAR levels in FSGS patients and controls, from the earliest available date to May 1, 2018. A random-effects model with standardized mean difference (SMD) was used for meta-analyses. Risk of bias was assessed using the Newcastle-Ottawa quality assessment scale.

Results

A total of 187 articles were screened, and the final analysis included 13 articles. In comparison to healthy controls, serum suPAR levels were significantly increased in pFSGS patients (SMD, 1.07, 95% confidence interval (CI) 0.65 to 1.48; participants = 814; studies = 9, I ² = 85%). Higher suPAR levels were also found in patients with pFSGS compared to those with minimal change disease (SMD 0.53, 95% CI 0.22 to 0.84). Of note, such a difference was not found in pediatric groups (SMD 0.42, 95% CI -0.13 to 0.96) while it was more evidently noted in adult patients (SMD 1.32, 95% CI 0.90 to 1.74). Serum suPAR levels did not differ between pFSGS patients in remission compared to those in active proteinuric state (SMD 0.29, 95% CI -0.30 to 0.88). Comparison with membranous nephropathy and IgA nephropathy showed no significant difference.

Conclusions

Our meta-analysis demonstrated that, in comparison to both healthy controls and controls with minimal change disease, suPAR levels were significantly higher in adult patients with pFSGS. suPAR levels did not differ between pFSGS patients during the initial period of diagnosis and those in remission.